"The two B-2 Spirit bombers made a nonstop round trip from Whiteman Air Force Base, Mo.," reportsThe New York Times's Choe Sang-Hun. "It was the first time the U.S. military publicly confirmed a B-2 mission over the Korean Peninsula." According to reports the B-2s flew over South Korea's west coast.

Obviously, the test run demonstrates that the U.S. has the capability of flying that far without actually crossing into North Korea and it appears to be meant to send a message that the U.S. is willing to defend South Korea against the North. There's also probably some historical symbolism thrown in. Hun adds, "After suffering from the American carpet-bombing during the 1950-53 Korean War, North Korea remains particularly sensitive about U.S. bombers."